Stairway

ABSTRACT

An improved stairway and method of fabricating same incorporating treads and risers secured to one another at right angles, with the risers each having a receiving portion at its upper end for receiving fasteners therein. The fasteners extend from each side into notches in the stringers for holding the associated riser and tread in place. The tread of the next pair of tread and riser has a bent-over portion cooperating with the riser of said first pair of tread and riser. Fabrication of the improved stairway is simplified, for once the stringers are in place and the first pair of tread and riser joined to the stringers, the succeeding pairs of tread and risers are joined to the stringers merely by positioning the fasteners into the notches and then placing the bent-over portion of the tread onto the preceding riser.

'United States Patent [1 1 1111 3,914,912

Rosenberg [45] Oct. 28,- 1975 STAIRWAY I 94,645 8/1969 France .f. ..52/1s3 Inventor: Marvin osenberg, Glencoe, In. 1,445,355 5/1956 France 182/228 [73] Assignee: Midwest Iron Works, Inc., Chicago, Primary EXaml-ner ]ohn Attorney, Agent, or Firm-Seymour Rothstein [22] Filed: Aug. 22, 1974 [21] Appl. No.: 499,782 [57] j ABSTRACT Related Application Data An improved stairway and method of fabricating same [63] Continuation-impart of Ser; No. 448,705, March 6, incorporating treads and risers secured to one another 1974, abandoned. 1 at right angles, with the risers each having a receiving 1 portion at its upper end for receiving fasteners therein; [52] US. Cl. 52/188 The fasteners extend from each side into notches in [51] Int. Cl. E04F 11/12 the stringers for holding the associated riser and tread [58] Field of Search 52/ 185, 191, 188, 183, in place. The tread of the next pair of tread and riser 52/182, 184, 189, 665, 758 F; 182/228, 194 has a bent-over portion cooperating with the riser of said first pair of tread and riser. Fabrication of the im- [56] References Cited proved stairway is simplified, for once the stringers are UNITED STATES PATENTS in place and the first pair of tread and riser joined to 2,377,994 6/1945 Cocken 52/182 the w the sucFeeding pairs of q q risers 2,649,126 8/1953 Tinnerman 52/758 F are Jmed to the smnges merely by Iwsmonmg the 3,268,031 8/1966 Hampson 182/228 x fasteners into the notilhes and then Placing the bent- WFOREIGN PATENTS OR APPLICATIONS over portion of the tread onto the preceding riser.

570,621 7/ 1945 United Kingdom 52/ 182 10 Claims, 8 Drawing Figures Mll- STAIRWAY BACKGROUND OF THE INVENTION riser and tread sizes to determine the numbers required.

for a particular application. The risers and treads are manufactured in a factory, as are the stringers or side supports, the railings and the landing. The components are delivered to the job site for assembly to form the stairway, which may be a row stairway having a single run or a stairway having a landing intermediate the two levels or floors, with stairway runs extending from each level or floor to the landing. The stairway can be fabricated entirely from metal, or if desired, provision can be made for supporting concrete or the like on or in the treads.

More recently, it was suggested that an entire stair- FIG. 3 is a fragmentary perspective view illustrating the association between a pair of tread and riser and associated stringer;

FIG. 4 is a side view of a stringer, which has the upper surface thereof notched at spaced intervals so as to receive the fastener of a pair of tread and riser;

FIG. 5 is a cross-sectional view of the landing portion of the stairway taken generally along the line 5-5 of FIG. 2;

' FIG. 6 is a detailed view of a portion of the stairway taken generally along the line 6-6 of FIG. 5;

FIG. 7 is a fragmentary perspective view illustrating the association of components and including a modified tread and riser; and

FIG. 8 is a cross-sectional view of the modified tread and riser of FIG. 7.

way connecting a floor to a landing be prefabricated at a shop, together with support masts. See Seegers US. Pat. No. 3,707,814. The components are shipped to the site for assembly. Handling and shipment are difficult because of the bulk and weight of the prefabricated assembly. Different components are required for different jobs.

Another approach is found in Theisen US. Pat. No. 3,720,024. A prefabricated stackable stair unit includes a stair flight integrally secured to a half landing having a width approximating that of the stair flight. Handling and shipment are difficult because of the bulk and weight of each stair flight.

An object of this invention is to simplify stairway construction, as used for example, for interior tire and service stairs in high rise apartments and office buildings, and reduce fabrications costs by standardizing components and simplifying the assembly of such components on the job site.

Another object of this invention is to provide an improved stairway that incorporates joined treads and risers, the risers having fasteners retained at the upper ends for engagement in notches in the stringers, with the treads being disposed on the riser of a preceding pair of tread and riser.

Yet another object of this invention is to provide an improved method for fabricating a stairway comprised of a subassembly of riser and tread and stringers.

Other objects and advantages of the present invention will be made more apparent hereinafter.

BRIEF DESCRIPTION OF THE DRAWING There is illustrated in the drawings two specific stairways embodying the present invention, wherein:

FIG. 1 is an elevation view of a stairway embodying principles of the present invention;

FIG. 2 is a plan view of the stairway taken generally along the line 22 of FIG. 1;

DETAILED DESCRIPTION OF THE PRESENT INVENTION Referring to FIGS. 1 and 2 there is illustrated a stairway 10 in a typical building 12. The building 12 may be high rise apartment building or an office building which is provided with a floor 14 and a floor 16. FIG. 1 is illustrative of but one of a plurality of like stairways in the building. The stairway 10 comprises a lower run 18, a landing 20 and an upper run 22.

The building 12 may comprise a plurality of beams or uprights 24, 25 suitably interconnected by cross members or interconnecting members which carry the floors or the buildings may be of concrete forms as sometimes utilized today. The floor 16 may include horizontal beams or cross members 26, 27 suitably secured to the uprights 24 and 25. The landing 20 is supported by suspension rods 30, 31 and the stringers 34, 35 of the lower run 18 are secured to the channel 38 which forms a part of the landing 20. A first tread 40 and a riser 42 are secured to the stringers 34, 35'. The subsequent paris of treads and risers 44, 46 are joined to the stringers 34, 35 as will be more fully explained hereinafter. The pairs of tread andriser 44, 46 are all the same and thus, the workmen need only take several pairs and affix them one at a time as he progresses from the floor 14 toward the landing 20. Adding successive pairs of tread and riser along the upper run 22 will complete the bearing portion ofthe stairway 10. The railing comprising upright posts 50,51 and 52 as well as the rails 54, 56, 58 and 60 are secured in place. The platform plates 62, 64 are positioned upon the frame of landing 20 to complete the stairway construction. The frame includes elongated members 61, 63, 65 and cross members 67 and 69 that support platform plates 62 and 64.

Turning now to FIGS. 3, 4, 5 and 6 there is better illustrated the details of construction of the present invention. The pair of tread and riser is comprised of a separate tread 44 and a separate riser 46 joined to one another, as for example, by welding. The safety tread 44 comprises a planar portion 44a and a bent-over portion 44b.

The riser 46 comprises an upright planar portion 46a and a bent-over portion 46b adapted to encapsulate or retain a nut 66 therein. The nut may be welded or merely retained in place by means of a crimping or force fit. The nut 66 is threaded and is adapted to receive therein a fastener or bolt 68. It will be understood that the head of the bolt 68 is spaced from the nut 66 or surface of the riser 46 at a distance somewhat greater than the thickness of the stringer 34. The

3 stringer'34 is provided with an upward-opening notch 70 that is adapted to receive the fastener 68 therein.

Thestringer 34 as best shown in FIGS. 3 and 4, comprises an elongated plate member having a plurality of openings 72, 74 punched or otherwise formed in each end thereof for receiving fastening means to connect the stringer as required to the upright posts of the railing or to permit connection of the stringer to the frame,- work or platform. The fastening means may comprise bolts or other fasteners, or if desired, the parts can be welded together. The stringer 34, for example, has a plurality of spaced apart upwardly-opening notches 70 provided'in the upper edge thereof for receiving the fasteners 68 of associated pairs of treads and risers.

It will be understood that the length of the stringer will be determined initially based upon the design of the building, including the height of the floors and the tread and riser sizes. Once the length of stringers and the number of pairs of tread and riser required to provide the stairs for that portion of the run have been determined, the job can be specified. The pairs of treads and riser can be fabricated from metal and suitably assembled at a plant. The fabricated pairs of tread and riser are shipped to the job site for installation. The stringers likewise can be cut to length and punched or otherwise formed as shown, for example, in FIG. 4, at the factory and shipped to the job site for assembly.

At the job site the suspension rods 30, 31 are secured in depending relationship to the channels 26, 27 comprising the floor 16. The frame of landing 20 comprising interconnected channels or like support members 61, 63, 65, 67 and 69 is then secured to the suspension rods 30, 31 in a variety of suitable fashions. Stringers 34, 35 are affixed to the landing 20 in parallel relationship, preferably with the notches in each stringer in horizontal alignment. The workmen can then commence to assemble the units comprised of pairs of treads and risers to the stringers 34, 35. The fastener 68 is positioned in the lowermost notches 70 in the stringers 34, 35 and the first riser and partial tread are secured in place.

It is to be noted that the bent-over portion 44b of a tread 44 cooperating with the bent-over portion 46b of an adjacennt riser 46. It is preferred that the bent-over portion 54b of the tread 44 extends at least 180 and preferably 2 so as to make a more secure fit with the complementary bent-over portion 46b of the cooperating riser 46, and to essentially interlock the complementary engaging parts. Successive pairs of treads and risers are then positioned in place on the stringers as the workmen proceed from the floor 14 toward the landing 20. When each pair of treads and risers are properly positioned in place, the workmen can tighten the fasteners 68 in order to permanently secure the components together. With the completion of the lower run 18, the workmen can proceed in a similar fashion to affix the pairs of treads and risers to the stringers 76 and 78 which comprise the upper run 22.

A butt plate may be provided at the upper stair or alternatively, the platform 62 may have a curved bentover portion 62b complementary to the configuration of the bent-over portion 46b of the uppermost riser on the lower run.

Turning to FIGS. 7 and 8, there is shown a modified tread and riser embodying the present invention. The tread 144 includes a planar portion 144a and a bentover portion l44b at the front thereof. The rear of the planar portion 144a is suitably secured to the riser, as for example, to a flange on the riser, as shown. The bent-over portion 144b includes a curved wall 1440 that extends from the planar portion 144a, a downwardly extending wall 144d and a wall 144e cooperating with the downwardly extending wall to define a V.

The riser 146 includes a planar upright wall 146a and a bent-over or receiving portion 146b that retains nut 166 that in turn receives fastener 168. The receiving portion 146b includes wall 146C extending from wall 146a and wall 146d depending from wall 146C. The end portion of wall 146d is provided with a curved wall and planar extension 1466.

The bent-over portion l44b of a tread 144 cooperates in interlocking relationship with the bent-over portion l46b of a riser 146. The parts are dimensioned so that preferably there is some tension between the V defined between walls 144d and 144e of the tread and the curved portion of wall l46e of the riser.

The riser and tread construction shown in FIGS. 7 and 8 is readily fabricated as assembled. The cooperating bent-over portions of the tread and riser produce the desired results, but do not require as precise tolerances as the embodiment of FIGS. 1-6.

There has been provided by the present invention standardized components for a stairway that can be fabricated off-site and readily assembled on-site. Fabrication costs are reduced and principles of the present invention are applicable to a number of variations. It will be appreciated that in addition to the basic stairway construction shown including an upper run and a lower run, the invention will be equally applicable to a row stair. In addition, it will be understood that the treads can be fabricated so as to receive poured concrete or a concrete slab in those constructions where a concrete base is required on the treads, rather than a steel base.

While a preferred embodiment of the present invention has been shown and described, it will be understood that this embodiment may be altered and modified without departing from the true spirit and scope of the invention as defined in the following claims:

What is claimed is:

1. In a stairway comprising stringers supported in parallel relationship in a structure, and treads and risers on said stringers, the improvement comprising said stringers having notches at spaced positions along the upper surfaces thereof in horizontal alignment with the notches in the cooperating stringer, the treads and risers comprising cooperating members secured one to the other, the risers each having a receiving portion at the upper end for receiving a fastener at each side, each fastener extending into the receiving portion at the upper end and being retained in one of said notches in said stringer for holding and affixing the associated riser in place on the stringers, the tread of the next pair of tread and riser having a bent-over portion at the front thereof cooperating with the receiving portion of said riser of said first pair of tread and riser, and engaging same in interlocking relationship in a direction transverse to the length of the tread and riser and said second tread and riser and successive treads and risers being joined to the stringers" and to one another in the same manner to form the stairway in situ.

2. A stairway as in claim l wlierein the tread includes a planar portion and a curved bent-over portion at the front thereof, the curved bent-over portion extending at least 180.

3. A stairway as in claim 1 including a receiving member retained in the receiving portion of the riser adjacent each side thereof and being adapted to receive a fastener said fasteners being directly adjustably retained in the receiving portions so as to better hold a riser to the stringers.

4. A stairway as in claim 3 wherein the receiving portion of the riser is formed integral with a planar portion, the receiving portion being bent over at least 180.

5. A stairway as in claim 1 wherein the receiving portion of the riser includes wall means engaging nut means for receiving the fastener, said wall means including a depending wall, and the bent-over portion of the tread includes wall means forming a V for engaging the end portion of the depending wall.

6. A stairway as in claim 5 wherein the bent-over portion of the tread includes a curved portion extending from the planar portion, a downwardly extending wall and an upwardly extending wall cooperating with the downwardly extending wall to define a V that is adapted to lockingly engage with the end portion of the depending wall of the wall means of the receiving porcooperating members secured one to the other to form a unit, the riser having a receiving portion at the upper end for receiving a fastener at each side, each fastener extending into the receiving portion at the upper end, and tread having a portion adapted to engage with the upper end of an associated riser, comprising the steps of fixing the stringers with the notches in cooperating stringers being disposed in horizontal alignment, joining a unit to the stringers by engaging the fasteners therein in associated notches in the stringers, engaging the tread of one unit with the riser of preceding unit, and engaging successive units in the stringers in a similar fashion with the tread of a successive unit cooperating with the riser of a preceding unit.

8. A method as in claim 7 wherein the fasteners are tightened to secure each unit in place on the stringers after positioning.

9. A method as in claim 7 wherein a bent-over portion is formed on the tread complementary to the receiving portion on the riser and including the step of frontally interlocking the complementary engaging bent-over portion of a tread of one unit with the receiving portion of a riser on the preceding unit.

10. A method of claim 7 including interlocking the tread of one unit with the riser of a preceding unit by engaging cooperating portions of the tread and riser in a direction transverse to the length of the tread and riser. I 

1. In a stairway comprising stringers supported in parallel relationship in a structure, and treads and risers on said stringers, the improvement comprising said stringers having notches at spaced positions along the upper surfaces thereof in horizontal alignment with the notches in the cooperating stringer, the treads and risers comprising cooperating members secured one to the other, the risers each having a receiving portion at the upper end for receiving a fastener at each side, each fastener extending into the receiving portion at the upper end and being retained in one of said notches in said stringer for holding and affixing the associated riser in place on the stringers, the tread of the next pair of tread and riser having a bent-over portion at the front thereof cooperating with the receiving portion of said riser of said first pair of tread and riser, and engaging same in interlocking relationship in a direction transverse to the length of the tread and riser and said second tread and riser and successive treads and risers being joined to the stringers and to one another in the same manner to form the stairway in situ.
 2. A stairway as in claim 1 wherein the tread includes a planar portion and a curved bent-over portion at the front thereof, the curved bent-over portion extending at least 180*.
 3. A stairway as in claim 1 including a receiving member retained in the receiving portion of the riser adjacent each side thereof and being adapted to receive a fastener said fasteners being adjustably retained in the receiving portions so as to better hold a riser to the stringers.
 4. A stairway as in claim 3 wherein the receiving portion of the riser is formed integral with a planar portion, the receiving portion being bent over at least 180*.
 5. A stairway as in claim 1 wherein the receiving portion of the riser includes wall means engaging nut means for receiving the fastener, said wall means including a depending wall, and the bent-over portion of the tread includes wall means forming a V for engaging the end portion of the depending wall.
 6. A stairway as in claim 5 wherein The bent-over portion of the tread includes a curved portion extending from the planar portion, a downwardly extending wall and an upwardly extending wall cooperating with the downwardly extending wall to define a V that is adapted to lockingly engage with the end portion of the depending wall of the wall means of the receiving portion of the riser in a direction transverse to the length of the tread and riser.
 7. A method of fabricating a stairway comprising stringers having notches at spaced positions along the upper surfaces thereof and a tread and riser comprising cooperating members secured one to the other to form a unit, the riser having a receiving portion at the upper end for receiving a fastener at each side, each fastener extending into the receiving portion at the upper end, and tread having a portion adapted to engage with the upper end of an associated riser, comprising the steps of fixing the stringers with the notches in cooperating stringers being disposed in horizontal alignment, joining a unit to the stringers by engaging the fasteners therein in associated notches in the stringers, engaging the tread of one unit with the riser of a preceding unit, and engaging successive units in the stringers in a similar fashion with the tread of a successive unit cooperating with the riser of a preceding unit.
 8. A method as in claim 7 wherein the fasteners are tightened to secure each unit in place on the stringers after positioning.
 9. A method as in claim 7 wherein a bent-over portion is formed on the tread complementary to the receiving portion on the riser and including the step of frontally interlocking the complementary engaging bent-over portion of a tread of one unit with the receiving portion of a riser on the preceding unit.
 10. A method of claim 7 including interlocking the tread of one unit with the riser of a preceding unit by engaging cooperating portions of the tread and riser in a direction transverse to the length of the tread and riser. 